The invention is applicable to communication systems, wherein a plurality of frequency channels are closely spaced and/or slightly overlapped. This is done in order to increase the number of channels within a given frequency range. In satellite communications and particularly in television receive only (TVRO) satellite communications isolation between channels is provided by changing from horizontal polarization to vertical polarization or vice versa between each pair of adjacent channels. Therefore, it is necessary to switch from horizontal polarization to vertical polarization or vice versa between adjacent channels at the transmitting and receiving antennas.